Google Instant Arrives on iPhone. And Android, Too.

Originally announced back in September, Google Instant for mobile went live today, bringing the auto-populating search results to iPhone and Android devices. Like on the desktop, Instant displays search results as you type into the Google.com search field in mobile Safari, as well as Android’s browser.

It isn’t enabled by default on the iPhone, requiring you to activate it by clicking a link below the search bar when you first navigate to Google.com. It’s also available only in the U.S. initially, and not at any of the international domains like Google.ca, etc. If you aren’t seeing it yet, Google advises that you wait a moment and refresh. You have to be using iOS 4 on the iPhone, or Android 2.2 or above for the feature to work, too. Google has a demo video, which you can see below.

I found that it works about as quickly as the desktop version, and that on the iPhone, the functionality is somewhat limited by the fact that your on-screen keyboard obscures most of your results. Still, all you have to do is hit the “Done” button to view your aut0-populated list, so it is a lot faster than searching via Google’s mobile site used to be. In fact, since you don’t have to load a new page, and you can usually see right away if you have your desired top hit, navigating one-handed becomes much faster overall.

It’s a nice addition, and possibly more useful than its desktop counterpart, since it caters to the limitations of mobile browsing. I tested on 3G and Wi-Fi connections. Let us know how well it’s working for you.